Recently, electronic devices with universal serial bus (USB) interfaces are widely used as the peripheral devices of computer systems. In addition, the types of the electronic devices with USB interfaces are more diverse. For example, the electronic devices include flash drives, keyboards, mouse devices, speakers, or the like.
However, in many situations, the electronic devices with USB interfaces still have some drawbacks. For example, since the types of the electronic devices with USB interfaces are diverse, the electronic devices are possibly incompatible with different operation systems or different software/hardware devices. In case that the incompatibility problems occur, the USB interfaces that are originally in the normal working state are suddenly in a disabled state. In the disabled state, the electronic device cannot be normally operated.
When the electronic device is in the disabled state, the user may plug and pull out the electronic device again or restart the operation system to read the electronic device again. In such way, the USB interface is restored to the normal working state. That is, the conventional electronic devices with the USB interfaces are not user-friendly.
Therefore, there is a need of providing an improved UBS detecting method and an improved USB expansion device in order to overcome the drawbacks of the conventional technologies.